8-wire 120v Honeywell conversion to 24v NEST Learning
#41
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Found a built in board as recommended by my parents condo HVAC guy. This will do the exact same PnP all in one transformer & relay board 

#42
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Hey,
Just wanted to say great thread, going to be swapping out two of my thermostats as well.
Mine's a bit different than both of you.
5 Relays + Transformer + Wiring should be good? -- Any reason you guys are going with the NEST and not a LYRIC T5/T6?
L1 (HOT) BLACK
HEAT (ORANGE)
FAN-HI (BROWN)
L2 (N) WHITE
COOL (YELLOW)
FAN-MED (BLUE)
FAN-LO (RED)
Just wanted to say great thread, going to be swapping out two of my thermostats as well.
Mine's a bit different than both of you.
5 Relays + Transformer + Wiring should be good? -- Any reason you guys are going with the NEST and not a LYRIC T5/T6?
L1 (HOT) BLACK
HEAT (ORANGE)
FAN-HI (BROWN)
L2 (N) WHITE
COOL (YELLOW)
FAN-MED (BLUE)
FAN-LO (RED)
#44
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Join Date: Jan 2019
Location: Canada
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Hi farfetchd,
Sounds like you have the exact same wiring, except you're missing the Blue common wire for the fans. I assume that the blue common is not necessary and you can splice it to the white neutral instead, but double-check with someone more knowledgeable. Always question everything you read on the internet.
If you are open to losing a fan speed (eg. medium), I would recommend getting the 4-relay board instead of the 8, which is half the size. It would make for a much smaller circuit box.
With regards to going with Nest, my brother (where this was implemented) is into automation and has a bunch of Google products already. Just easier to have them all work together.
--Dan
Sounds like you have the exact same wiring, except you're missing the Blue common wire for the fans. I assume that the blue common is not necessary and you can splice it to the white neutral instead, but double-check with someone more knowledgeable. Always question everything you read on the internet.

If you are open to losing a fan speed (eg. medium), I would recommend getting the 4-relay board instead of the 8, which is half the size. It would make for a much smaller circuit box.
With regards to going with Nest, my brother (where this was implemented) is into automation and has a bunch of Google products already. Just easier to have them all work together.
--Dan
#45
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My previous update now seems a little ambiguous. I was referring to the "blue common" in my scenario. In yours, the blue appears to be your "Fan Med" and it is purple in mine (could just be semantics). Regardless, you should be able to figure it out.

Last edited by vandacca; 01-06-20 at 11:36 AM. Reason: correcting mistake.
#47
Welcome to the forums.
I don't see anything made/listed for a 1/4hp motor.
What is the amperage on your 1/4hp motor ?
A 1/8hp motor uses approx 3.8A@120v. A 1/4hp motor use approx 5.5A@120v.
Relay Outputs HI, MED, LOW: 1/8 HP @ 115 VAC; 10A @ 240 VAC resistive max.
What is the amperage on your 1/4hp motor ?
A 1/8hp motor uses approx 3.8A@120v. A 1/4hp motor use approx 5.5A@120v.
#49
I can see by the page views that this has become a hot topic. When threads get too long and have many members problems...... it gets confusing. I've started a new thread on this topic and it can be found HERE.
Please feel free to start your own thread which is the best choice.
You can refer to this thread for reference,.
Please feel free to start your own thread which is the best choice.
You can refer to this thread for reference,.